Some electrochromic devices are devices that change color state when an electrical current is applied and can switch back and forth between those different color states. Once an electrochromic device has been switched into a state it can remain in that state even after any applied electrical current or voltage is removed. The change in color state may be between different colors, including switching between a mirror state or a transparent state or a translucent state. Electrochromic devices can be capable of being tinted from a low transparency state to many different intermediate translucent (or semi-transparent) states to high transparency states. Historically this technology has been difficult to scale to large size window glass for architectural or transportation usage. In part, this is because in larger scale electrochromic devices an “iris” effect is pronounced, where the device changes color more quickly towards the outside edge and more slowly towards the center of the device. This can be unappealing for use in buildings, or in transportation vehicles using larger substrates such as automotive window, buses, trains, or boats. Additionally, larger scale electrochromic devices can have slow switching speeds when transitioning between states.
Electrochromic devices can be laminated to carrier glass, for various purposes including streamlining the manufacturing process, improving the strength of the device, and packaging the device into an insulated glass unit (IGU). For example, U.S. Pat. No. 7,710,671 describes methods of producing electrically tintable thin film devices including providing a large format glass substrate, fabricating electrically tintable thin film devices on the large format glass substrate, cutting the large format glass substrate into a plurality of electrically tintable pieces, each electrically tintable piece including one of the plurality of electrically tintable thin film devices, providing a plurality of window glass pieces, matching each one of the plurality of electrically tintable pieces with a corresponding one of the plurality of window glass pieces, and laminating each of the matched electrically tintable pieces and window glass pieces. By way of further example, US 2011/0261429A1 describes electrochromic device laminate fabrication processes including fabricating electrochromic devices on substrate daughter panes, cutting each of the electrochromic devices into individual electrochromic devices, and laminating each of the individual electrochromic devices to a separate outer laminate glass panes.
Tiling devices by arranging multiple devices on a single substrate has been described for different types of display technologies where the devices do not have a clear state and are not designed for use as a window. Some of the tiled displays employ strategies to create a single device with invisible seams by hiding the inactive areas by overlapping adjacent tiles, or spacing the tiles close enough together that the pixel pitch does not vary across a seam between the tiles. For example, US20070001927A1 describes a tiled display, including display elements containing bistable materials that can include electrochemical materials, electrophoretic materials, electrochromic materials, magnetic materials, and chiral nematic liquid crystal materials, that are covered by a single protective layer. US20070001927A1 also includes the feature of the individual display elements overlapping to hide inactive areas, and create a continuous display area over multiple display elements. Additionally, U.S. Pat. No. 6,370,019 describes a tiled display with no visible seams between the tiles enabled by the spacing between the pixels separated by the tile seam being the same as the spacing of pixels on the tile. U.S. Ser. No. 09/250,329 also includes the possibility that a backpanel may be provided for the physical mounting and interconnection of the tiles to form a display. While these types of strategies are acceptable for displays, they typically are not applicable to the seams of tiled transparent devices, such as tiled electrochromic devices designed for use as windows.
Corresponding reference characters indicate corresponding parts throughout the drawings. Additionally, relative thicknesses of the layers in the different figures do not represent the true relationship in dimensions. For example, the substrates are typically much thicker than the other layers. The figures are drawn only for the purpose to illustrate connection principles, not to give any dimensional information.